Method of and apparatus for automatic cleaning and automatic control of mechanical grates



July 29. 1924.; 1,503.092

R A. CARTER. JR

METHOD OF AND APPARATUS FOR AUTOMATIC CLEANING AND AUTOMATIC CONTROL OF MECHANICAL GRATES Filed June, 12, 1923 2 Sheets-Sheex l v I-NVENTOR Agat ATTORNEY R. A. CARTER. JR

METHOD OF AND APPARATUS FOR AUTOMATIC CLEANING AND AUTOMATIC CONTROL OF MECHANICAL GRATES Filed June 12. 1923 2 Sheets-Shea 2 IN VEN TOR M W ATTORNEY Patented July 29, 19.24.

ROBERTA. CARTER, JR, or BAYBIIDGE, BROOKLYN, NE YORK.

METHOD OF AN D APPARATUS FOR AUTOMATIC CLEANING AND AUTOMATIC CONTROL OF MECHANICAL GEA'IES.

Application filed June 12, 1923; Serial No. 644,880.

To all whom it may concern:

Be it known that 1, ROBERT A. CARTER, Jr., a citizen of theUnited States, residing at Bay Ridge, Brooklyn, county of Kings, State of New York, have inventedcertain new and useful Improvement in Methods of and Apparatus for Automatic Cleaning and Automatic Control of Mechanical Grates, of which the following is a speci fication taken in connection with the accompanying drawings.

My invention relates to the method of automatic cleaning and also to automatically controlling a mechanical grate. My invention broadly consists in the method of controlling the operation of the grate, by means of the heat of the fire bed.

My invention further relates to controlling the cleaning of different portions of the undersurface of the'fire bed by means of the heat of the particular portion of the fire bed. That is, by my invention the heat of different portions of the fire bed controls the operation of the grate. v

My invention further relates to a'water gas generator which can be continuously operated by means of my invention.

"My invention further relates to an automatic controlled mechanical grate thatwill automatically cease operating, either in whole or in part, when owing to too rapid operation it'has started to draw down hot fuel instead of ashes and clinkers.

1 preferably employ my invention with a water'gas machine, although it is to be understood that my invention is not to be limited to this use. It may be applied upon boilers, stills, producers, b-last furnaces, and thelike wherever a mechanically operated grate may be used to withdraw the ashes from beneath lire.

In the operation of a water gas generator it is the practice, now generally in use, to equip the generator with stationary bars, set with a uniform distance between them, upon which the fuel bed rests.

It is customary in the operation of a water gas generator to feed fuel each hour as the fuel in the generator is consumed and at the close of from six to eleven hours to discontinue the operation, open the'cleaning doors and remove the accumulation of ash and clinker from beneath the fire by hand. This method of ash removal requires from to 120 minutes for a gang of from 4 to 6 men; is very hot, arduous labor; is usually attended with considerable loss of fuel from the generator and is attended with an upsetting of the heat balance in the carburetor and superheater to which the above mentioned generator is attached.

Many attempts have been made to introduce continuous mechanical removal of the ash and the CllIlliQltfil'Sl) to save labor, second to save the fuel consumed and lost during cleaning period, third to save the operating time lost during the cleaning, fourth to maintain uniform conditions of operation in the generator and fifth to maintain uniform heat in the carburetor and superheater.

It has been attempted to use mechanically operated grates with water gas generators. In these mechanical grates the grate bars are rotated by a. worm wheel, gearing with a worm shaft, the grate bars being preferably arranged in pairs. In practice such a mechanical grate has been found unsatisfactory. While such "a mechanical grate is positive inits action and continuous in its operation, it has no flexibility and cannot adjust itself to the varying conditions and needsof a water gas generator, or any similar device where the fuel and consumption is not, uniform.

If the fuel used in a water gas generator were uniform from day to day and from hour to hour, in the percentage of its ash content; and if this increment of ash were constant in character and the rate of production, and likewise the rate of fuel con suinp'tion were constant at all times; and if the rate of fuel consumption and ash accumulation were the same in the center of the machine as in points nearer the walls,

then it would be possible that a grateof this nature could be set at the properrate of rotation to withdraw the ash as it accumulates; on the one hand not allow ng the ash to build up above the grate, and on the other hand not withdrawing and wasting the incandescent fuel.

But such conditions with regard to the character of the fuel and ash accumulation do not exist in practice. \Vide variations occur in percentage of ash in fuel, in the rate of production and in the consumption of fuel in differentparts I of the generator. Therate of movement which is suitable at one time, is not suitable at another, and the rate of movement whichis suitable at. one point in the grate area, is not suitable at another. Therefore, in the operation of any of the now known mechanical grates, while the ash is building up at one point, the fire is being pulled down from the fire bed at.

, another point and wasted.

shutting down of the machine and the removal of the grate with the attendant eX- pense of its replacement.

By my invention I so control the operation of the grate that either in whole, or

in part, it will automatically cease to operate when, owing to too rapid operation,

there is a tendency to withdraw incandescent fuel. p

I lVith my invention, when one of the bars of the grate, due to withdrawing the ash too rapidly, tends to become too hot, that particular grate bar is automatically made to cease rotating. The effect is first, that no damage is done to that part of the grate; second, there is a cooling off of that grate bar owing to the accumulation ofash above it resulting from continued operation of the generator, thus permitting that grate bar automatically to take up again its suspended operation.

This automatic control of the grate bars is accomplished in my invention by using the different degrees of heat of different portions of the fire bed itself, to control the amount of cleaning that the different portions of the fire bed shall be subjected to. a

I have shown by way of illustration one adapation of my invention in which the control of the cleaning is effected by means of the different portions of the undersurface of the fire bed heating and expandingthe different grate bars. In the particular form shown in the drawings, by way of illustration, it is the linear expansion of the different grate bars themselves, when heated beyond their normal temperature,

which automatically prevents the removal of hot coals from that portion of the fire .mit new ash and new clinker to form above the particular grate bar, thereby removing it from the live coals, and consequently permitting it to cool. As soon as it is cooled to the predetermined temperature it! will again be automatically thrown into gear, and will again clean that particular portion of the fire bed, it being understood that preferably each one of'my grate bars is separately and automatically controlled.

My invention is adapted for general application and a wide range of structures can be employed, all of which will'come within the terms of my invention.

For purpose of illustration, and to show one adaptation of my invention, but of course, not the only one, I have shown it in connection with a water gas machine.

My invention further relates to certain methods, combinations and sub-combinations and details of construction all of which will be'more fully hereinafter described and pointed out in the claims.

In the accompanying drawings the same some of the worm wheels bein shown in plan;

Fig. 2 is a vertical section substantially on the line 22 of Fig. 1;

Fig. 3 is a vertical section, on an enlarged scale, showing one form of clutch which may. be employed;

Fig. 4; is a vertical section, on an en larged scale, of a detail showing the adjustable thrust bearing to adjust the limit of travel of the grate bar in that direction.

In the drawings 1 is a water gas machine provided with a plurality of rotating grate bars 2, 2, the bars being preferably arranged in pairs and adapted to rotate towards each other. On these bars, which are preferably square in cross-section for most of their length, I mount a plurality of disks 3, 8 arranging them staggered with relation to each other. Each disk is provided with a cutaway portion 4,4. The disks are arranged in pairs and each pair revolves towards each other, so that the cutaway portions act as cutting members and remove the accumulated ash and clinker above them; the weight of the fire bed serving to press new ash and new clinker into the path of the disks, as the fire burns and the grate bars rotate. The ash and clinker fall into the ash pit or bin 21 and are removed therefrom in any suit-- able manner.

It has been previously pointed out that in most all fire beds, and particularly so in a water gas generator, neither the fuel, nor the ash content is uniform; nor is the accumulation of the ash and clinker the same at the center of the fire bed and at p the circumference.

the rotation of the grate bars 2, 2 that By my invention I automatically control they will only be rotated to stoke the fire bed when there is sufiicient accumulation of ash and clinker above them to warrant their rotation and withoutwithdrawing live coal, each grate bar being independently and au tomatically controlled by the temperature of the particular portion of the fire bed which it supports. This will permit all the grate bars 2, 2 to be rotated at the same time,

or any one of them, the others being, for the moment, immovable.

In the apparatus, which I have shown as one embodiment of my invention, each grate bar 2 has a round portion 5 mounted in the bearing 6. On this portion 5 of the grate bar 2- is loosely mounted a worm wheel 7 to which is secured the concave member 8 of a cone clutch. To prevent lateral movement of the worm wheel 7 with its clutch member 8, I provide it with a groove 9 within; which fits retaining members '10, 10 secured to the bearing 6 by means of the bolts 11, 11. On the end of the cylindrical shaft 5, of the grate bar 2, is immovably secured the convex clutch member 12 of the cone clutch by means of the pin 13. The clutch members 8 and 12 are normally pressed into engagement by the spring 1 1.

The adjustable thrust bearing 15, Fig. 4, is withdrawn from the recess 16 in the bar 2 and is set at a predetermined position when the bar is cold so that when it starts to heat up, the expansion will be in that direction first, until the limiting temperature is reached, when being resisted by the thrustbearing 15 all subsequent movement will be in the other direction, compressing the spring 14 and releasing the clutch.

A worm shaft 18 is mounted at right angles to the grate bars 2, 2 and is provided with pairs of right and left worms 19, 19 (only one of them being shown) so that the grate bars 2, 2 will operate in pairs and rotate towards eachother when both are rotated 'by the worm shaft 18. r

In the operation of my device, as here illustrated, the worm shaft 18 always rotates each one of the worm wheels 7, and normally will rotate each one of the grate bars 2 by means of the spring 1 1 engaging the clutch members 12 and 8. When, however,any one or more of the grate bars 2, 2 has removed all the ash and clinker upon it and has thereby become unduly heated by so thatit can only expand linearly against the action of the spring 1 1. In so expand ing, however, it withdraws the clutch member 12 from engagement with the clutch member 8, permitting the latter clutch member with the worm wheel 7 to rotate idly, without rotating the particular grate bar 2 upon which it is mounted. This will then permit new ash and new clinker to accumulate above this particular grate bar 2 which will then be stationary, and as this accumulation increases the grate bar is cooled. The moment that it has cooled to its predetermined temperature it will contract, aide'd by the tension of the spring 14;, and will immediately again cause the clutch members 12 and 8 to engage so that that particular grate bar will again be operated to remove ash and clinker. This is true of all the grate bars '2 which are all separately and automatically controlled by the tem- 5 perature of the fire bed immediately above them.

This not only prevents the grate bars 2 from warping, bending, buckling or twisting, requiring the water gas machine to be shut down while they are being removed, but it permits the continuous operation of the water gas machine, with any variety of fuel and without wasting live coals.

Having thus described this invention in connection with an illustrative embodiment the'reof,*to thedetails of which I do not desire to be limited, what is claimed as new and what is desired -tov secure by Letters Patent is set forth in the appended claims.

What I claim is 1. The method of automatically cleaning a fire'bed, consisting in removing the ash and clinker, and employing the heat of the fire bed to itself directly control the rate of removal of theash and clinker from said fire bed. I

2. The method of automatically cleaning a fire bed, consisting in removing the ash and clinker, and employing the heat of the fire bed to itself directly control the rate of removal of the ash and clinker from one or more partsof the said fire bed.

3. The method of automatically cleaning 1 a fire bed, consistingin removingthe ash and clinker, and employing the heat of the to remove ashes and clinkers and employing the heat of the fire bed to automatically discontinue'the operation of oneo-r more of the grate bars when the proper-amount of ash and clinker have, been removed from the fire bed above said grate bar or gratebars.

' grate bars.

- the expansion of the grate, bars t prevent movement temporarily of one or more of the grate bars topermit new ash and new clinker to again build up abovesaid bar or bars. n v I 7. Themethod of automatically cleaninga fire bed consisting in rotating grate bars to remove ashand clinker, and employing the heat of the furnace to expand one or more of the grate bars to prevent rotation of said bar or bars when theyhave reached a certain predetermined temperature to permit new ash and new clinker to again form above them. p i 7 v8. The method of automatically cleaning all or different portions of the under surface .ofa lire bed by removing all or fractional parts of the ash and clinker consisting in automatically controlling the rate of cleaning by the temperature of different portions of the under surface of the fire bed.

9. The method of cleaning a Water gas generatorconsisting in automatically removing ashes and clinkers from the fire bed by moving the grate bars on which the fire bed rests, and employing the heat of the fire bed to automatically control the movement of the grate bars so that'o-ne or more of them may be from time to time rendered immovable to permit new ash and new clinker to accumulate above them.

10. The method of cleaning a water gas generator consisting in automatically removing ashes and clinkers from the fire bed by rotating the grate bars on which the fire bed rests, and employing the heat of the fire bedto automatically control the rotation of the grate bars so that one ormore of them may vbe from time to time rendered, immovable to permit new ash and new clinker to accumulate above them.

11. The combination inan automatically controlled mechanical grate, of rotatable grate bars, means to rotate them, and automatic means controlled by the expansion of said grate bars to -control the rotation of said grate bars.

12. The combination in an automatically controlled mechanical grate, of movable grate'bars, and means controlled by the heat of the grate bars to automatically stop the movement of said grate bars.

13. The combination in an automatically controlled mechanical grate of rotating grate bars, means to rotate them, and automatic means controlled by the expansion of the grate bars to disconnect and connect one or more of said grate bars from said rotating means.

14. The combination in an automatically controlled mechanical grate of grate bars adapted to. rotate in pairs towards each other, means to rotate said grate bars, discs on each grate bar, and automatic means controlled by the degree of heat of the grate bar to stop the rotation of one or more of said grate bars.

15. In a water gas machine adapted for continuous operation, the combination of rotating grate bars, means to rotate said bars, and automatic means controlled. by the heat at different portions of the undersurface of the tire bed to stop the rotation of one or more of said grate bars to pemit new ash and new clinker to again accumulate upon said bar or bars.

16. In a water gas machine adapted for continuous operation, the combination of rotating grate bars, means to rotate said bars, and automatic means controlled by the ore pansion of the grate bar or bars to stop the rotation of one or more of said grate bars to permit new ash and new clinker to again accumulate upon said bar or bars.

17. In an automatic controlled mechanical grate the combination of rotating expansible grate bars, driving members loosely mounted on the eXpa-nsible grate bars,- driven members connected to the expansible grate bars, spring means to normally connect the driving and driven members, when the grate bars are at their normal temperature and condition, said driving and driven members being disconnected when the grate bars are expanded by abnormal heat, and means to rotate the driving member.

18. In an automatic controlled mechanical grate the combinationof rotating grate bars, Worm wheels loosely mounted on the grate bars, clutch members connected to the 'Worm Wheels, clutch members connected to the grate bars, a worm shaft, springs to norbars, .Worm Wheels loosely mounted on the grate bars, clutch members connected to the Worm Wheels, clutch members connected to bers when the grate bars become overheated,

the clutch members again engaging when 10 the grate bars cool and contract and means ofadjustment to establish the temperature at which the clutch will disengage.

ROBERT A. CARTER, J R. Witnesses JNO. J. VIsBRooK, SADIE FERRELL. 

